1. Field of the Invention
The present invention generally pertains to a V-type two-cycle engine and, more particularly, to the air intake system of a two-cycle engine having a pressurized crank chamber.
2. Description of the Prior Art
V-type two-cycle engines, such as that represented by published Japanese patent application Hei 2-248628, are widely known in the art. This type of engine configuration includes two cylinder rows which are positioned approximately symmetrically on either side of a crankshaft to define the V-shape. In this type of two-cycle engine, separate air intake passages for each of the two cylinder rows are provided. In addition, a crankcase is attached to the cylinder block of each cylinder row to form a crank chamber therebetween.
A two-cycle engine constructed in a manner described above is subject to a short engine life for various reasons. For example, vibrations generated during operation of the engine tend to concentrate in the valley of the "V" formed by the cylinder rows. These vibrations must be absorbed by the cylinder block unless made very massive and heavy, cannot absorb these fatigue loads over a long period of time. Also, because the crank chamber is pressurized, there must be air intake connections on the side of the cylinders and in the crankcase for each of cylinder rows. These air intakes, when located on either side of the crankshaft in roughly symmetrical alignment, are also subjected to high vibrations from the intake system. These conditions invite the occurrence of poor seals in areas near the cylinder block and air intake passages, thereby causing decreased engine life.
Therefore, there exists a need in the art for a V-type two-cycle engine having a cylinder block and air intake arrangement which suppresses the vibrations in the air intake system to prevent decreased engine life yet which can be made smaller and lighter than known cylinder blocks.